Vat dyestuff and process of making same



' or hydro forl hydrogen.

UNITED STATES PATENT OFFICE,

ill LAXIMILIAN PAUL SCHMIDT AND OTTO LIMPAOH, OF BIEBRICH-ON-THE-BHINE,

GERMANY, ASSIGNORS, BY MESNE ASSIGNMENTS, TO GRASSELLI DTYESTUFF 'COB- 1oRArIoN, OF NEW YORK, N. Y., A 'CORPORATION OF DELAWARE.-

vn'r DYESTUFF AND PROCESS ORMAKING SAME.

' Ne Drawing. Application filed November 17, 1925, Serial No. 69,704.Renewed rebma 12, 1929.'

The presentinvention relates to new vat dyestufls and a process ofpreparing the same; more particularly it relates to the dye-v stufl's ofthe general formula:'

wherein X represents hydrogen or a monovalent substituent, at least oneB represents an alkyl roup, the other R stands for alkyl gen, G and Gbeing carbon atoms belonging to a benzene or naphthalene nucleus whichmaybe substituted.

"Our dyestufis are obtainable by pound of the following general formula:

wherein X represents hydrogen or a mono valent substituent and at leastone B stands for an alkyl group, the other B being alkyl @ur newdyestuffs yield on wool andcotton dyeings of excellent fastness and, asregards their properties, are much superior to 40 the hitherto knowndyestuffs of this kind obtainable from phenohydroxynaphthocarbazoles andisatin-2-derivatives. Thus, the dyestuff obtainable fromortho-toluhydroxyfnaphthocarbazole and isatin-2-anilide gives abeautiful bloomy black tint, the purity of which can be enhanced byboiling in an acidified bath. The correspondin dyestufi' pro.-

duced from chlorisatin-2-anili e gives On cotton dyeings of perfectfastness. Dyeings of similar fastness and shades are obtainable by meansof'the dyestufls produced from carhazoles alkylated at the nitrogenatom.

condensmg a reactive 1sat1n-2-der1vat1ve wlth a com- The dyestufi' soobtained forms a black crystalline powder which dissolves inconcentrated sulfuric acid to a bluish-black color. With an alkalinehydrosulfite a yellow Vat is obtained dyeing wool and cotton on exposure to the air black'tints. The dyestufl' has the most probableformula:

2. 24:,7 parts of ortho-tolu-5-hydroxynaphthocarbazole are heatedto-boilln for some hours with 29 parts of 5-chlorisain-2-parachloranilide; The dyestufi is worked up as indicated inExample 1. It forms a black powder which dissolves in concentratedsulfuric acid to a bluish-black solution. From an alkaline vat thedyestulf dyes wool and cotton black tints. The dyestufi has the mostprobable formula: 9

Similar dyestuffs, which are distinguished by a somewhat greaterfastness to chlorine, are Obtained by condensing with isatin-2ederivativesthe pheno-5-hydroxynaphthocarbazoles which are methylated atthe nitrogen atoni. a

By the teim isatin-2-derivativesl I under-f stand in the foregoingdescription and in-the lene nucleus.

following claims compounds which contain in 2-position of the nucleuscontaining nitrogen exchangeable groupsand in whichlthe ring attachedto--the 5-ring maybe {a substit-uted or unsubstituted benzeneornaphthalVe claim:

1. As new products the dyestuffs of the following general formula:

wherein X represents hydrogen or a monovalent substituent, at least oneR stands for alkyl, the other R for alkyl or hydrogen, and G and Crepresent carbon atoms belonging to a benzene or naphthalene nucleuswhich may be substituted, said dyestuffs forming black powdersdissolving in concentrated sulfuric acid to bluish-black solutions anddyeing wool and cotton from an alkaline vat on exposure to air blacktints.

2. As new products the dyestuffs of the following general formulawherein X represents hydrogen or chlorine,

an alkyl group, drogen or alkyl.

forming a black powder dissolving in concentrated sulfuric acid to abluish-black solution and dyeing wool and'cotton black tints from analkaline vat on exposure to air.

4. The process which comprises condensing an isatin-2-derivative with acompound of the general formula:

R n x f1 x v H 5 \X x v OH v wherein ,X represents hydrogen or amonovalent substituent, at least one R stands for and the other R beinghy- In testimony whereof we hereunto aflix our signatures. DR.MAXIMILIAN PAUL SCHMIDT. DR. OTTO ,LIMPACH.

